(function($) {

		$.suggest = function(input, options) {

			var $input = $(input).attr("autocomplete", "off");
			var $results = $(document.createElement("ul"));

			var timeout = false;		// hold timeout ID for suggestion results to appear
			var prevLength = 0;			// last recorded length of $input.val()
			var cache = [];				// cache MRU list
			var cacheSize = 0;			// size of cache in chars (bytes?)
			
			 $(input).val('');
			
			$results.addClass(options.resultsClass).appendTo('body');
			$('body').append('<div id="'+options.oldsuggestid+'" style="display:none;"></div>');

			resetPosition();
			$(window)
				.load(resetPosition)		// just in case user is changing size of page while loading
				.resize(resetPosition);

			$input.blur(function() {
				setTimeout(function() { $results.hide() }, 200);
			});


			// help IE users if possible
			try {
				//$results.bgiframe();
			} catch(e) { }


			// I really hate browser detection, but I don't see any other way
			if ($.browser.mozilla)
				$input.keypress(processKey2);	// onkeypress repeats arrow keys in Mozilla/Opera
			else
				$input.keydown(processKey2);		// onkeydown repeats arrow keys in IE/Safari*/
			
			$input.keyup(processKey);

			function resetPosition() {
				// requires jquery.dimension plugin
				var offset = $input.offset();
				$results.css({
					top: (offset.top + input.offsetHeight) + 'px',
					left: offset.left + 'px'
				});
			}

			function processKey(e) {

				// handling up/down/escape requires results to be visible
				// handling enter/tab requires that AND a result to be selected
				if (/^32$|^9$/.test(e.keyCode) && getCurrentResult()) {

		            if (e.preventDefault)
		                e.preventDefault();
					if (e.stopPropagation)
		                e.stopPropagation();

	                e.cancelBubble = true;
	                e.returnValue = false;
					selectCurrentResult();

				} else if ($input.val().length != prevLength) {

					if (timeout)
						clearTimeout(timeout);
					timeout = setTimeout(suggest, options.delay);
					prevLength = $input.val().length;
					setTimeout(function(){
						$("#"+options.oldsuggestid).text($input.val());
					},options.delay);
				}
			}

			function processKey2(e) {

				// handling up/down/escape requires results to be visible
				// handling enter/tab requires that AND a result to be selected
				if (/27$|38$|13$|40$/.test(e.keyCode) && $results.is(':visible')) {

		            if (e.preventDefault)
		                e.preventDefault();
					if (e.stopPropagation)
		                e.stopPropagation();

	                e.cancelBubble = true;
	                e.returnValue = false;
					switch(e.keyCode) {

						case 38: // up
							prevResult();
							break;

						case 40: // down
							nextResult();
							break;
							
						case 9:  // tab
						case 13: // return
							selectCurrentResult();
							break;
						
						case 27: //	escape
							$results.hide();
							break;

					}
					
				} else if ($input.val().length != prevLength) {
					
					if (timeout)
						clearTimeout(timeout);
					timeout = setTimeout(suggest, options.delay);
					prevLength = $input.val().length;
					setTimeout(function(){
						$("#"+options.oldsuggestid).text($input.val());
					},options.delay);

				}

				

			}


			function suggest() {

				var q = $.trim($input.val());

				if (q.length >= options.minchars) {

					cached = checkCache(q);

					if (cached) {

						displayItems(cached['items']);

					} else {
						
						$.get(options.source, {q: q}, function(txt) {
							
							$results.hide();
							var items = parseTxt(txt, q);
							displayItems(items);
							//addToCache(q, items, txt.length);

						},options.datatype);
						
						

					}

				} else {

					$results.hide();

				}

			}


			function checkCache(q) {

				for (var i = 0; i < cache.length; i++)
					if (cache[i]['q'] == q) {
						cache.unshift(cache.splice(i, 1)[0]);
						return cache[0];
					}

				return false;

			}

			function addToCache(q, items, size) {

				while (cache.length && (cacheSize + size > options.maxCacheSize)) {
					var cached = cache.pop();
					cacheSize -= cached['size'];
				}

				cache.push({
					q: q,
					size: size,
					items: items
					});

				cacheSize += size;

			}

			function displayItems(items) {
				
				if (!items)
					return;
				
				if (!items.length) {
					$results.hide();
					return;
				}

				var html = '';
				
				if(options.datatype=='json'){
					for (var i = 0; i < items.length; i++){
						html += '<li>'+items[i]+'</li>';
					}
				}else{
					for (var i = 0; i < items.length; i++){
						html += items[i];
					}
				}
				
				
				$results.html(html).show();

				$results
					.children('li')
					.mouseover(function() {
						$results.children('li').removeClass(options.selectClass);
						$(this).addClass(options.selectClass);
					})
					.click(function(e) {
						e.preventDefault();
						e.stopPropagation();
						selectCurrentResult();
					});

			}

			function parseTxt(txt, q) {

				var items = [];
				
				if(options.datatype=='json'){
					$.each( txt, function(key, val){
						var token = $.trim(val);
						if (token) {
							token = token.replace(
								new RegExp(q, 'ig'),
								function(q) { return '<span class="' + options.matchClass + '">' + q + '</span>' }
								);
							items[key] = token;
						}
	    			});
				}else{
					var tokens = txt.split(options.delimiter);
					// parse returned data for non-empty items
					for (var i = 0; i < tokens.length; i++) {
						var token = $.trim(tokens[i]);
						if (token) {
							token = token.replace(
								new RegExp(q, 'ig'),
								function(q) { return '<span class="' + options.matchClass + '">' + q + '</span>' }
								);
							items[items.length] = token;
						}
					}
				}
				
				return items;
			}

			function getCurrentResult() {

				if (!$results.is(':visible'))
					return false;

				var $currentResult = $results.children('li.' + options.selectClass);

				if (!$currentResult.length)
					$currentResult = false;

				return $currentResult;

			}

			function selectCurrentResult() {

				$currentResult = getCurrentResult();

				if ($currentResult) {
					$input.val($currentResult.text());
					$results.hide();

					if (options.onSelect)
						options.onSelect.apply($input[0]);

				}

			}

			function nextResult() {

				$currentResult = getCurrentResult();

				if ($currentResult){
					$currentResult
						.removeClass(options.selectClass)
						.next()
							.addClass(options.selectClass);
				}else{
					$results.children('li:first-child').addClass(options.selectClass);
				}
				var $currentResult = $results.children('li.' + options.selectClass);
				
				var $currentResult = $results.children('li.' + options.selectClass);
				if($currentResult.text()==""){
					$input.val($("#"+options.oldsuggestid).text());
				}else{
					$input.val($currentResult.text());
				}
				$input.unbind("keyup");

			}

			function prevResult() {

				$currentResult = getCurrentResult();

				if ($currentResult){
					$currentResult
						.removeClass(options.selectClass)
						.prev()
							.addClass(options.selectClass);
				}else{
					$results.children('li:last-child').addClass(options.selectClass);
				}
				var $currentResult = $results.children('li.' + options.selectClass);
				if($currentResult.text()==""){
					$input.val($("#"+options.oldsuggestid).text());
				}else{
					$input.val($currentResult.text());
				}
				$input.unbind("keyup");
				

			}

		}

		$.fn.suggest = function(source, options) {

			if (!source)
				return;
			options = options || {};
			options.source = source;
			options.delay = options.delay || 100;
			options.datatype = options.datatype || 'json';//可以为json或html
			options.resultsClass = options.resultsClass || 'ac_results';
			options.selectClass = options.selectClass || 'ac_over';
			options.matchClass = options.matchClass || 'ac_match';
			options.minchars = options.minchars || 1;
			options.delimiter = options.delimiter || '\n';
			options.onSelect = options.onSelect || false;
			options.maxCacheSize = options.maxCacheSize || 65536;
			options.oldsuggestid = options.oldsuggestid || 'oldsuggestid';

			this.each(function() {
				new $.suggest(this, options);
			});

			return this;

		};

	})(jQuery);
